Author/Authors :
Diana M. Dufour-van den Goorbergh، نويسنده , , P. Descouvemont ، نويسنده ,
Abstract :
The View the MathML source radiative capture reaction is investigated with a two-cluster generator-coordinate method. A multi-channel description of the 18Ne wave functions as a superposition of the View the MathML source and View the MathML source channels is used. The 17F and 14O wave functions are defined in the shell model involving s, p and sd orbitals. The model provides a good overall description of the 18Ne spectroscopy at energies typical of nova and x-ray burst processes. In particular, the 3+1 state, an s-wave resonance dominating the reaction rate at temperatures above 5×108 K, is well described. We find a proton width Γp=21.1 keV, in good agreement with the experimental value Γp=18.0±2stat±1sys keV. Its gamma width, unknown experimentally, is Γγ=33 meV, similar to values deduced from the shell model, and used in astrophysics (Γγ=30±20 meV). The non-resonant (E1) as well as the resonant contributions (M1,E2) of the astrophysical S-factor are determined. At zero energy we find S(0)=3.5 keV-b. The corresponding View the MathML source reaction rate is calculated, and compared with previous approaches.